Ensure you are wearing safety glasses 2. Take the petri dishes and label then 1, 2, 3, and 4. 3. Add 20 drops of silver nitrate solution to each petri dish. 4. Add 20 drops of sodium chloride to petri dish one and three. Mix with stirring rod and observe the reaction. 5. Add 20 drops of sodium iodine to petri dishes 2 and 4. Mix with stirring rod and observe reaction. 6. Put petri dishes 1 and 3 in the sunlight for 5-10 minutes. 7. Put petri dishes 2 and 4 in a dark place, away from any light. 8.
After 5-10 minutes, observe the reaction and record results. Risk Assessment: RISK| PRECAUTION| WHAT CAN BE DONE INCASE| Chemical solutions getting into eyes| Be careful while handling chemical solutions, always wear safety glasses| In case this happens, inform teacher and wash eyes thoroughly wash eyes with clean cold water| Staining hands with solution| Wear safety gloves and handle with care| Inform teacher; wash affected area under cold water. | Sniffing the gas produced after reaction| Do not open petri dish once the solutions are mixed.
Toxic gasses may be present| Inform teacher, immediately seek medical attention| Results: The Sodium Chloride NaCl was decomposing faster than Sodium Iodine NaI in the sunlight. Whereas the petri dishes placed in the dark location as a control showed no signs of decomposition or change in colour. Solution| Reaction in presence of sun light| NaCl + AgNO3 | Yes| NaBr + AgNO3| Yes| Solution| Reaction in absence of sun light| NaCl + AgNO3| No| NaBr+ AgNO3| No| Discussion: 1. Sunlight has less Ultra Violet radiation compared to a special Ultra Violet lamp. 2.
The Essay on Bacteria Petri Dish
Bacteria Bacteria are one celled organisms that are found almost everywhere. Bacteria live in soil, air, water and food. They also live in and on plants and animals. Bacteria can be found on our bodies in places such as our noses, mouths and intestines. Most bacteria measure from 0. 3 to 2. 0 microns in diameter. This means that bacteria can only be seen through a powerful microscope. Bacteriology ...
By having the control dishes, we can compare the effects of the UV radiation on the salts. By not having the dark controls, we can’t make a comparison 3. NaCl+AgNO3 AgCl (s) + NaNO3 NaBr + AgNO3 AgCl (s) + NaNO3 NaI + AgNO3 AgI (s) +NaNO3 4. a. Br– Br + e— b. Ag+ + e– Ag Conclusion: The silver nitrate with sodium iodide turned clear in the presence of sunlight. While the solver nitrate with the sodium chloride produced a green colour. The reaction with sodium iodide was more obvious and faster compared to the reaction with the sodium chloride.
